The present invention relates generally to the field of managing the routing of information over an integrated global communication network, such as the Internet, and, more particularly, to the methods and systems for reserving routing paths for routing information over the network.
As is well known, the Internet is a vast collection of computers that communicate over a packet network via high-speed communication paths ranging from ISDN to T1, T3, FDDI, SONET, SMDS, OT1, etc. A personal computer typically accesses the Internet through a modem on a user""s xe2x80x9cPlain Old Telephone Servicexe2x80x9d (POTS) line or through a switched ISDN. Alternatively, a personal computer can access the Internet through a X.25, Frame Relay (FR) or Asynchronous Transfer Mode (ATM) connection on a high-speed local area network (LAN) or wide area network (WAN). Connecting a personnel computer to the LAN requires a card known as a LAN adapter that plugs into the computer""s expansion bus. Once Internet access is established, the Internet communicates information from the source computer to a destination over a routing path using any one of a number of protocols, such as the Internet Protocol (IP).
With the increased routing of multimedia (voice, video and data) calls over the Internet, there continues to be a growing demand for modifications to the routing component of the Internet infrastructure to support real-time quality transmission of information. For example, video applications have characteristics including file size, flow rate and sensitivity to delay that distinguish them from other applications that share the same network. A single video file can be hundreds of megabytes or gigabytes long, whereas traditional data is significantly shorter. Further, a traditional data application is sent over a network as a burst of packets, whereas a video application is sent as a continuous stream of data which must be delivered quickly and regularly. When packetized, transmission delays must not vary by more than a few milliseconds. Data that arrives too late is discarded resulting in diminished quality of display. Moreover, the frames occupy space in queues, delaying the rest of the traffic and possibly causing such traffic to be discarded as well. Thus, the key requirement is to reduce the end-to-end packet delays (e.g. jitter) in order to satisfy real-time delivery constraints and achieve the necessary high nodal throughput (e.g. message latency) for the transfer of real-time voice and video.
Currently, the management of routing between the Internet and the various routers are commonly performed over a signalling network, such as Resource Reservation Protocol (RSVP), which visits routers in the network and attempts to make a resource reservation to obtain routes that are capable of routing particular multimedia information. A more detailed description of RSVP may be found in R. Braden et al., Resource ReServation Protocol (RSVP)xe2x80x94Version 1 Functional Specification,Internet Draft,June 1997, ftp://ftp.isi.edu/internet-drafts/draft-ietf-rsvp-spec-16.txt, which is incorporated herein by reference.
The current Internet routing structure, however, lacks the ability to provide advanced reservation of optimal routing paths for such real-time multimedia information. Such advanced reservation is desirable in reducing jitter and achieving high message latency in the transmission of such information. It is therefore desirable to improve the routing of multimedia information through the integrated global communication network such that the desired transmission is achieved.
In one aspect, the invention features a system for managing the routing of information to a destination through a packet network that includes a plurality of routers, wherein each router in the packet network is linked to at least one other router by a communication medium. The system comprises a routing processor for receiving a routing query specifying a destination to which the information will be routed and a memory for storing at least one characteristic of each of the routers in the packet network. The processor determines a route for the transmission of the information based on the routing query and on the characteristics stored in the memory, wherein the route comprises at least two of the routers.
In another aspect of the invention, the invention features a system for routing information to a destination, which comprises a packet network and a routing processor. The packet network includes a plurality of routers, wherein each router is linked to at least one other router by a communication medium. The routing processor receives a routing query signal from a first one of the routers and information concerning at least one characteristic of each of the remaining routers. The routing processor then determines a transmission path for routing the information through the packet network based on the routing query and on the characteristics stored in the memory, wherein the route comprises at least two of the routers.
In still another aspect of the invention, the invention features a method for managing the routing of information to a destination through a packet network, wherein the network includes a plurality of routers and each router is linked to at least one other router by a communication medium. The method comprises the steps of receiving a routing query specifying a destination to which the information will be routed at a routing processor, storing at least one characteristic of each of the routers in a memory and determining a route for the transmission of the information based on the routing query and on the stored characteristics. The transmission path comprises at least one router in addition to the first router.
In yet another aspect of the invention, the invention features a method for managing the routing of information to a destination in a packet network that includes a plurality of routers, wherein each router is linked to at least one other router by a communication medium. The method comprises the steps of receiving a routing query signal from a first one of the routers and information concerning at least one characteristic of each of the remaining routers and determining a transmission path for routing the information through the packet network. The transmission path comprises at least one router in addition to the first router. Such routing can be implemented for both Internet and Intranet traffic.